Choc-Arcade has Lily's two favorite things: a chocolate shop and an arcade! Not only that, but Choc-Arcade's loyalty program rewards Lily with free game tokens every time she buys chocolates. There is a proportional relationship between the number of chocolates Lily buys, x, and the number of free game tokens she gets, y. x (chocolates) y (tokens) 2 6 3 9 4 12 6 18 What is the constant of proportionality? Write your answer as a whole number or decimal.